The subject invention relates to systems and methods for selectively locking a position of a steering column.
Use of electronic steering column locks (ECLs) has been expanding due to the proliferation of pushbutton start ignition across many cars and trucks. The purpose of a column lock (either electronic or mechanical) is to inhibit rotation of the steering shaft, thereby preventing steering of the vehicle. Doing so increases the difficulty of vehicle theft by pushing or towing a vehicle away while parked.
Electronic column lock modules are typically implemented by use of an electric motor to generate motion, gears for increasing torque, and a leadscrew or cam profile to convert rotation to linear motion used to extend or retract a lock bolt that blocks steering shaft rotation. An electronic controller is also included in the module to receive lock and unlock commands from the vehicle, control motor motion, and sense bolt position.
The disadvantage of the current ECL implementations is related to the use of a leadscrew or cam to generate the linear motion required to retract or extend the lock bolt. Both leadscrews and cams are friction interfaces, and therefore have an inherent inefficiency to them, leading to a requirement for upsized motor and electronics to generate the torque required to actuate the mechanism.
Accordingly, it is desirable to have an improved system and method for selectively locking a position of a steering column.